It would all be over, the British thought, in a jiffy. In, out, and done. Wars could be slogs, mind you, but many were quick affairs that inevitably led to victory and honor enough to go around.

In fact, sending men into battle might be just what Britain needed to do to avoid going soft in the early years of the 20th century. “The severest war wreaks little practical injury,” declared a newspaper commentator who lacked the benefit of imagination or foresight.

Others feared the worst. There was the woman who’d seen the horror of deprivation and mistreatment during a war in South Africa, and the labor and women’s suffrage activists who watched helplessly as their causes evaporated amid an epidemic of European war fever.

But really, how bad could things get? Awful beyond anyone’s comprehension, shows author Adam Hochschild in To End All Wars: A Story of Loyalty and Rebellion, 1914-1918, his gripping new book, an instant classic of military and social history.

Writers like Barbara Tuchman have expertly told the story of World War I, which we now see as a ridiculous, futile war launched by nations that plowed forward heedlessly into the abyss. But there’s still more to understand, and Hochschild uses his expert storytelling skills to take a fresh look at the fighting on both the front lines and the home front. Everyone comes alive in this tale – soldiers and politicians, peace activists and warmongers, bereaved families and a horrified British nation.

Much of the book focuses on those who fought against the war, either at first or later when its horrors became known. They were voices in the wilderness in the early days of the war, isolated even from their former allies on the left. “It required rare courage to resist,” Hochschild writes. (The volunteer soldiers and sailors, of course, had their own brand of courage.)

Among the elites, the glorious honor of war held sway at the beginning. “The Hun is at the gate!” proclaimed a war-crazed Rudyard Kipling, while a young sailor wrote that God had “matched us with his Hour … and wakened us from sleeping.” Both poets would discover war’s power to steal lives in their prime.

Hochschild, who finds the war to be abhorrent and unnecessary, is well versed in the role of new technology and the stupendous stubbornness of clueless generals. Simple barbed wire, of all things, played a huge role by stifling advances and contributing to the massive carnage. Tanks, machine guns, and poison gas added to the chaos as military leaders tried to focus on what they considered most important: their outdated and useless cavalry forces.

Through memoirs and letters, Hochschild captures the evolution of the war as its horrors slowly dawn on the troops and their families back in Britain, despite the efforts of propagandists and apologists.

At home, war opponents gained numbers over time as the government tried to push naysayers into prison (along with 6,000 conscientious objectors) while not creating martyrs to the cause. “It would be hard to find a more distinguished array of people ever behind bars in a Western country,” Hochschild writes, pointing to imprisoned protesters who became political leaders and even a Nobel Prize winner for literature.

Throughout the book, Hochschild captures intricate details from the love lives of those on all sides to the occasional bizarre irony, like a “top-secret devil’s bargain” that allowed the British to give rubber to the Germans in return for tens of thousands of pairs of binoculars. The deal, which helped both sides cope with shortages, throws Hochschild for a loop: What on earth were they thinking?

The question fills every page of “To End All Wars,” whose title reflects the great irony of the conflict. The only weakness is that the author focuses mainly on Britain and gives short shrift to the experiences of other countries.

Ultimately, the Great War would set the stage for the century to come: a revolution here, a defeated and disgraced country there, and new lines on maps that created boundaries out of thin air.

As Hochschild writes, “the First World War itself has remained in our lives, below the surface, because we live in a world that was so much formed by it and by the industrialized total warfare it inaugurated.”

We’ll never know if a bolder commitment to peace, wisdom, or morality would have saved the world or created an even larger mess. One thing is clear: We’re still paying the price for the folly and failure of a war that began much more than it ended.